 ABC News. I'm Mark Remillard. The first presidential debate of the 2024 election cycle is just a few hours away. Former President Trump and President Biden set to face off in what will be the first time a sitting president debates a former one. The Biden campaign sees this as a real jumpstart moment, a chance for them to break through to a larger audience. And they hope those critical undecided voters who haven't really engaged in this race yet.